View Larger Map 521 Schuylkill Avenue, CO Investigation By admin on March 7, 2014 in Recent Calls 0918: AHCO and East End dispatched to 521 Schuylkill Avenue for a CO alarm activation. E776 and E778 en-route, update from county, will be Access Services building. Units on scene, CO monitoring turned up negative, oil burner checked. Possible weak battery alarming, nothing else found. Units cleared shortly after.